Variable as Placeholder Math Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

medium
A rectangle has area 24 cm² and width 4 cm. Use a variable to find the length.

Solution

  1. 1
    Let ℓ\ell be the unknown length (a placeholder for one value).
  2. 2
    Area formula: ℓ×4=24\ell \times 4 = 24.
  3. 3
    Divide both sides by 4: ℓ=6\ell = 6 cm.

Answer

ℓ=6 cm\ell = 6 \text{ cm}
The variable ℓ\ell acts as a placeholder for the single unknown length. Once we solve, the placeholder is replaced by its specific value.

About Variable as Placeholder

A variable acts as a placeholder — a letter or symbol (like x, n, or y) that stands in for an unknown or changing number in a mathematical expression or equation. It represents one specific unknown value that satisfies a given condition.

Learn more about Variable as Placeholder →

More Variable as Placeholder Examples

Example 1 easy

In the equation [formula], what specific value does [formula] represent?

Example 3 medium

Maria has some stickers. After giving away 8, she has 15 left. Write an equation and find how many s

Example 4 easy

Find the value of [formula] in [formula].

Example 5 medium

I think of a number, double it, and add 5 to get 19. What is my number?

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